class Bond
  def initialize(atom1,atom2)
    @atom1 = atom1
    @atom2 = atom2
  end
  
  def getAtomAtOtherEndOfBond(atom)
      if atom == @atom1 then
        return @atom2
      end
      if atom == @atom2 then
        return @atom1;
      end
      raise "This atom is not part of this bond";
  end
end
